Carbonaceous and vapor-burning furnace



(No Model.) 4 Sheets-Sheet 1.

' W. MoOLAVE. GARBONAGEOUS AND VAPOR BURNING FURNACE. No. 499,642. Patented June 13, 1893.

(No Model.) 7 4 Sheets-Sheet 2.

' McOLA GARBONAGEOU D VAPOR ING FURNACE.

No. 499,642. Patented June 13,1893. Y

Ki 9 9 I I 1555*] i H I (No Model.) 4 Sheets-Sheet 3.

W. MOCLAVE.

OARBONAOEOUS AND VAPOR BURNING FURNACE.

No. 499,642. Patented June 13, 1893.

Thim- (No Model.) 4 Sheets-Sheet 4.

W. MOOLAVE. GARBONAGEOUS AND VAPOR BURNING FURNACE.

No. 499,642. Patented June 13, 1893.

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WILLIAM MCOLAVE, OF SORANTON, PENNSYLVANIA.

CARBONACEOUS AND VAPOR-BURNING FURNACE.

SPECIFICATION forming part of Letters Patent No. 499,642, dated June 13, 1893.

Application filed January 13. 1893. Serial No. 458,233. (No model.)

- ton, in the county of Lackawanna and State of Pennsylvania, have invented certain new and useful Improvements in a Combined Solid Carbonaceous and Vapor-Fuel-Burning Furnace; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention consists in a novel construction of furnace for burning solid, carbonaceous fuels on a grate or fuel supporting bed by the introduction of a compound hot blast of mixed air and steam, or a compound hot blast of mixed air, steam, and hydrocarbon vapor, up through the mass of burning solid, carbonaceous fuel, such blast being introduced through the rear or side walls of the furnace, back of the bridge wall, into a large heating flue-chamber or chambers of a width singly or unitedly, ordinarily, nearly as Wide as the flame flue above it, and extending, in short furnaces, the whole length of said flame flue, and in very long furnaces asuitable distance backward from the bridge wall; and the air and the whole compound blast heated by the heat of conduction from the said flame flue and discharged under pressure in a mixed and heated condition into an inclosed ash pit and up through a mass of burning solid, carbonaceous fuel on a grate or fuel supporting bed.

In the accompanying drawings, Figure 1 is a vertical longitudinal section of my improved furnace as constructed and organized with means for furnishing a compound steam and air blast. Fig. 2 is a longitudinal section of the furnace on a plane below the flame flue bed. Fig. 3 is a broken section on the same plane as Fig. 1, illustrating a rectangular blast heating chamber, instead of ablast heating chamber contracted by tapering it rearwardly as in Fig. 1. Fig. 4 is a broken horizontal section, showing a furnace with two separated blast heating chambers with a central partition wall between them. Figs. 4* and 4** show horizontal sections of a furnace on the line of the blast heating chamber or blast inlet, the air duct being arranged in the side wall of the furnace, in rear of the bridge wall. Fig. 5 is a cross section of a boiler furnace and boiler, looking toward the rear wall, and steam jetting devices applied in the air duct of said wall. Fig. 6 is a perspective view of one of the metallic plates forming the support for the bottom of the flame flue of the furnace. Fig. 7 is a view looking at the rear end of the furnace, and showing a system of pipes connected with a boiler and with a liquid hydrocarbon tank, and leading into the air duct and air and blast heating chamber of the furnace, and discharging the compound hot blast intov the ash pit and up and through the mass of solid carbonaceous fuel.

A in the drawings represents afurnace wall, B a tubular steam boiler, O a flame flue extending to the rear furnace wall, connecting with the flues of the boiler and discharging at 0 into a stack flue.

A is the bridge wall; A brick work of the bottom of the flame flue, and F strong ribbed plates applied, preferably, upon inwardly extended jogs of the side walls, and extending entirely across and beneath the brick work A of the bottom of the flame flue. \Vhen the furnace is constructed with a partition and two blast heating flue chambers, these plates are made shorter and one of their ends rest on the partition wall. The under face of these plates is, preferably, made smooth so as to offer no obstruction to the passage of the hot blast beneath them.

G is a hot blast chamber constructed between the bottom A of the furnace, and bottom A of the flame flue O. This chamber extends, preferably, when the furnace is short, from the rear wall to the bridge wall A and communicates with the ash pit I but in very long furnaces it may be constructed to terminate short of the rear wall, as illustrated in Figs. 4*, 4*? This chamber is, preferably of a backwardly tapered form like that shown in Figs. 2, 4, 4*, 4**, so as to not impede the forward flow of the hot blast into the ash pit; but I may find it necessary in some constructions of furnaces to make the chamber with square corners at its rear. and have the air duct receptacle or passage Kof less diameter than the entrance end of the chamber, as shown in Fig. 3. The diameter of the chamber at its largest part, is, preferably, made nearly equal to the width of the brick Work of the bottom of the flame fiue, but it may be made narrower-for some furnaces; and the top surface of the bottom of the furnace wall which aids in forming this chamber, as well as the vertical side walls serve the best purposes when made smooth, as such construction will facilitate the flow of the hot blast through the chamber into the ash pit. The grate or fuel supportingbed J is placed on a plane somewhat higher than the hot blast chamber,and is at the front end of the furnace.

The air duct receptacle K is, preferably,

made flaring as shown in Fig. 1, and it may be provided with a metallic bolting plate or device K. To this bolting device the flange a of an air duct L is bolted, as shown. By this construction the duct can be removed so as to admit access into the hot blast chamber for clearing out, repairing or any other purpose. In Figs. 4*, 43*, the air duct L is shown applied in the side Wall of the furnace in rear of the bridge wall, and at a point which will subject the air and blast to a large portion of the heat conducted through the bottom of the flame flue; and thus insure its being heated to a proper temperature before it passes into the ash pit, and thence into the fuel.

In the air duct a steam jetting device M'in form, preferably, of a hollow ring, with jet orifices, is set, and this jetting ring is connected preferably with the steam dome of the boiler by means of the pipe M leading to the front of the furnace, turning back and entering the dome. At the front of the boiler the pipe M is provided with a regulator or cut-ofi'f cock N, to which is connected, by a suitable joint I), a pendent rod for opening and closing it conveniently. A means for connecting other pipes is provided at b on the vertical rear leg of the pipe. 7

In Fig. 6 I have shown a system of pipes corresponding with that shown and described and claimed in my application, Serial No. 456,261, filed December 24, 1892, whereby the supply of liquid hydrocarbon is forced by live steam from a tank 1 by a water piston, and mixed with steam in a branch pipe 2 of the steam pipe 3, and conducted into a vaporizing chamber or coil 4, and the mixture therefrom forced into the air duct L, and thence into the hot blast chamber, thence into the ash pit and up into the fire along with air drawn into the duct by the suctional forceof the steam, which air is heated with the other elements of the blast in its passage through the hot blast chamber.

The mechanism, as shown in Fig. 7, is not claimed here specifically, nor in combination with an air duct separate from the specific furnace herein described, and therefore no further description of the same need be given here; and for an understanding of its particular operation, reference is made to my shutting cock 6 and opening all the other cocks mentioned, the hydrocarbon, mixed with steam, will be jetted into the hot blast chamber and thence into the ash pit and up through the fire. I contemplate having the discharging portion of the steam pipe, or the discharging end of the mixed steam and hydrocarbon pipe, entered into the duct or discharge pipe of a fan blower, as illustrated in' Fig. 3 of Letters Patent No. 485,820, granted to me November 8, 1892, for the same purpose as set forth in said patent.

The great utility of my invention results mainly from the construction of a furnace with the hot blast chamber in the special manner described, in combination with means for supplying the blast of either air and steam, or air, steam and hydrocarbon, and introducing either of such blasts at the rear end of the hot blast chamber.

It will be understood that the air drawn by the steam or steam and hydrocarbon vapor, through the wide hot blast chamber, is prevented from seriously cooling the steam and hydrocarbon vapor in their passage beyond the air duct, as the mixture, when it gets into the chamber G, is heated by conduction of heat from the flame flue through the brick work, and plates on the bottom of said flue bed, and by the time the blast passes into the ash pit the steam and hydrocarbon vapor and air are restored to a temperature which will prevent chilling of the fire on the grate, and thus the most beneficial results will be secured by the use of air and steam combined, or air, steam and hydrocarbon vapor combined.

In constructing furnaces with air ducts in the rear wall, it has been usual to employ straight or zig-zag pipes of small diameters, but in such constructions steam jetting rings or other mechanical blasting devices whereby air and steam, or air, steam, and hydrocarbon were supplied under the fuel or fire supporting bed or grate, have not been used; or, at least, have not been successfully used. But, even if it should be found that it has been proposed to use such blasting devices in connection with small pipes, the benefits derived therefrom would be so slight that their use would be finally abandoned, as will be apparent from the following reasons:

The essential difference between a tube of about the same diameter of the outlet end of blower duct and that of a Wide chamber flue extending backward from the bridge wall of the furnace a considerable distance under the flame flue is this:

First. The flow of the blast in a small straight tube between said points is too rapid to absorb much of the heat through which it passes.

Second. The flow of the blast in a small straight tube between said points being too slight to absorb much of the heat, and should the tube be made zig-zagging for the purpose of keeping the blast for a longer time'subjected to the action of the heat beneath the flame flue then the friction of such a long tube and the many changes of direction occasioned by the elbows of such a tube, would materially destroy the effective force of the blast, and would also cause a change in the proportion of air to the amount of steam in the blast, for the reason, that the steam having highpressure to project it forward will'go on through the ash pit, while the air having only the projective force given it by the frictional surface of the ingoing jets, would be to a great extent retarded by said friction and change of direction. This want of proper proportion of steam and air would serve to defeat proper combustion in the solid, carbonaceous fuel, for reasons already well known to the art.

Third. In contradistinction to the foregoing retarding and combustion defeating features of a small tube, either arranged straight or zigzag, it is evident that a wide flue chamber leading from the rear wall, or from a point consid-, erably in rear of the bridge wall, to the ash pit, largely if not wholly avoids the defects named, for the reason that the velocity of flow of the blast in such a flue is lessened nearly proportional to the increase of volume, and, therefor, has more time to absorb heat in passing under the bed of the flame flue; again, it will present a heat absorbing surface nearly if not wholly equal to the width and length of the flame flue bed above, and will intercept and absorb a large volume of heat that would otherwise be conducted downward into the ground and be practically lost to the furnace in two ways-first, by being lost to the general heatof the furnace,--and,second, by not rendering a more highly heated and therefore more effective blast in the production of better combustionin a bed of solid carbonaceous fuel.

Fourth. The blast'when issuing from a wide flue chamber, which is nearly the Width of the ash pit, is discharged into said ash pit, and thence up into a bed of solid carbonaceous fuel more uniformly than when discharged from a small tube, for the reason that it enters with a full broadside discharge into said ash pit.

What I claim as my invention is 1. A furnace provided beneath its flame flue bed with a hot blast flue chamber or chambers extending rearward from the bridge wall of the furnace, and provided with an air duct or ducts in its wall or walls, and with a'mixed steam and hydrocarbon vapor jetting device or devices applied in connection with the air duct or ducts, and connected with a hydrocarbon supply pipe and a steam generator pipe, substantially as described.

2. In combination with a furnace provided with a flame flue bed andahot blast compartment beneath said bed, an air duct receptacle K in the rear wall of the hot blast compartment, a bolting plate provided in said air duct receptacle, and an air duct device L having a bolting flange a, substantially as described.

3. A furnace provided with a hot blast flue chamber beneath the bottom of the flame flue bed, and with an air duct in its wall in rear of the bridge wall, said chamber having its top surface formed of metallic plates which rest on the side walls and support the brick work of the flame flue bed, substantially as described.

In testimony whereof I hereunto afflx my signature in presence of two witnesses.

WILLIAM MCCLAVE.

Witnesses:

E. T. FENWIOK. CAssELL SEVERANCE. 

